1. Field of the Invention
The invention is directed to a switchable solar heating device for a gas turbine with at least one compressor stage and at least one turbine stage and to a gas turbine having a switchable solar heating device of this kind.
2. Related Art
In the turbine stages of a gas turbine, entropy of a gas is converted into mechanical energy. Prior to this, the entropy of the gas is correspondingly increased by one or more compression steps in a compressor and combustion of a fuel.
For example, DE 29 48 306 C2 and DE 196 51 645 C2 disclose an additional switchable solar heating device by which the gas can be preheated by a solar heater before being fed to a combustion chamber. Fuel is sprayed into this combustion chamber and the occurring mixture of fuel and compressed, preheated gas is burned. In this way, the entropy of the gas can be increased in an environmentally friendly way by solar energy and the performance of the gas turbine is accordingly increased, or its fuel consumption is decreased, so as to reduce the environmental burden.
In order to bypass the solar heating device and guide the gas directly from the compressor to the turbine under unfavorable climatic conditions in which efficient use of the solar heating device is not possible or for maintenance and repair work without high pressure losses in the solar heating device due to long pipelines, DE 196 51 645 C2 provides two separate 3/2-way valves upstream and downstream of the solar heating device which connect the compressor and turbine electively via the solar heating device or a bypass. In DE 29 48 306 C2, three 2/2-way valves are arranged for this purpose in the inlet and outlet of the solar heating device and the bypass. Both solutions require a relatively high expenditure on construction and control technology and disadvantageously increase pressure losses in the gas.